Enzymatic conversion of benzo(a)pyrene leading predominantly to the diol-epoxide r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene through a single enantiomer of r-7, t-8-dihydroxy-7,8-dihydrobenzo(a)pyrene. Benzo(a)pyrene is metabolically and stereospecifically converted by mixed-function oxidases of rat liver microsomes and epoxide hydratase (glycol hydro-lyase (epoxide-forming), EC 4.2.1.63)to the single enantiomer (-)r-7,t-8-dihydroxy-7,8-dihydrobenzol (A) pyrene. This enantiomer is further metabolized stereoselectively by the mixed-function oxidases to predominantly the diol-epoxide, r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzol(a)pyrene in which the 7-hydroxyl and the 9,10-epoxide are trans. Other unidentified metabolites are also formed from the r-7,t-8-dihydroxy-7,8-dihydrobenzo(a)pyrene. Racemic r-7,t-8-dihydroxy-7,8-dihydrobenzo(a)-pyrene is converted metabolically to both r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene and r-7,t-8-dihydroxy-c-9,10-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene. The diol-epoxides are unstable in aqueous medium, and their identification and characterization as r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene and r-7,t-8-dihydroxy-c-9,10-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene were accomplished by the identity of their tetrahydroxytetrahydrobenzo(a)pyrenes hydrolysis products with those of the authentic synthetic compounds with respect to mobility on high-pressure liquid chromatography and mass and ultraviolet absorption spectral analysis. The diol-epoxides were also reduced in the presence of NADPH to distinct trihydroxypentahydrobenzo(a)pyrenes. Since the synthetic racemic r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene is very highly mutagenic in mammalian cells, we suggest that it is the metabolically formed diol-epoxide that may be an ultimate carcinogenic form of benzo(a)pyrene.


BCG immunotherapy in chronic myelocytic leukemia. In 16 patients with chronic myelocytic leukemia an attempt to retard the myeoblastic transformation was carried out by means of repeated BCG administration in the period of remissions resulting from chemotherapy. Vaccinations were repeated at intervals of 4 weeks with doses of 2 mg of Mycobacteria by scarification. The time of uninterrupted remissions maintained with BCG vaccinations only ranged from 2 to 28 months, on the average 7.4 months. In this group 2 patients died and the duration of follow-up in the remaining cases ranges from 16 to 106 months, average 43.5 months. The survival time in the group of 16 patients with the same disease, who died after treatment with cytostatics only, was shorter ranging from 12 to 83 months, 32 months on the average. In one patient BCG vaccination was followed by tuberculosis of a supraclavicular lymph node.


Photoaffinity labeling and quaternary structure of the acetylcholine receptor from Torpedo californica. Membrane fragments from electric tissue of Torpedo californica containing nicotinic acetylcholine receptor are composed of four different polypeptide chains with molecular weights of 40,000 (alpha), 48,000 (beta), 62,000 (gamma), and 66,000 (delta). The alpha and beta chains are still present in all and gamma and delta in some of the receptor preparations after Triton X-100 extraction and purification by affinity chromatography. All components of the receptor react covalently with the photoaffinity label 4-azido-2-nitrobenzyltrimethylammonium fluoroborate, the delta chain incorporating less of the reagent as compared to the alpha and beta chains. Agonists and antagonists containing a quaternary ammonium group protect all chains against the label; the principal neurotoxin from Naja naja siamensis protects the alpha chain only. We conclude that the alpha chain binds the neurotoxin from Naja naja, the alpha and beta chains are involved in the binding of ligands with quaternary ammonium groups, and the function of the gamma and delta chains remains to be determined.


Preliminary analysis of 1H and 13C spectral and relaxation behavior in methionine-enkephalin. Nuclear magnetic resonance studies on the conformational dynamics of the pentapeptide H-Tyr-Gly-Gly-Phe-Met-OH are reported. This peptide, for which the generic trivial name "methionine-enkephalin" has been suggested, is pharmacologically active as a ligand for the mammalian opiate receptor(s). The studies reported are parallel investigations in two solvents (dimethylsulfoxide and water) of: 1H and 13C high resolution spectral assignments; 1H and 13C spin-lattice relaxation times, temperature dependence of amide proton chemical shifts, and half-times for chemical exchange or amide protons. From these data we conclude that the tyrosine side chain of methionine-enkephalin exhibits restricted motion with respect to the main peptide backbone of the molecule. On the other hand both the phenylalanyl and methionyl side chains are undergoing intramolecular reorientation with relatively high frequency.


Detection of different types of damage in alkylated DNA by means of human corrective endonuclease (correndonuclease). Corrective endonuclease (correndunclease) activity of HeLa cells was assayed with alkylated DNA. Double-stranded, covalently closed DNA from phage PM II was treated with methyl methanesulfonate, N-methyl-N-nitrosourea, beta-propiolactone, or diepoxybutane to introduce alkylated bases and alkali-labile sites into the DNA. The damaged DNA was incubated with an extract of HeLa cells that catalyzes the formation of breaks at apurinic sites in double-stranded DNA. Methylated DNA was broken at every alkali-labile site by the HeLa correndonuclease, which indicated that these sites are similar to the apurinic sites produced by heating at acid pH. DNA alkylated with beta-propiolactone or diepoxybutane containing the same number of alkali-labile sites was broken to a far lesser extent. This indicates the presence of a second type of alkali-labile damage that is correndonuclease-insensitive.


Short-lived methylated messenger RNA in mouse kidney. In experiments originally designed to examine selective turnover of methylated "caps" in renal mRNA, we observed that [3H]methyl label decayed from mRNA containing poly(A) with a half-life of 1-2 hr. (Caps are blocked, methylated mRNA sequences of the general structure m7GpppNm p(1 or 2)Np.). To distinguish between metabolism of short-lived mRNA and discriminate turnover of "caps", we compared residual [3H]methyl label in 5' and 3'mRNA fragments prepared from mRNA isolated during the decay period. Hydrolysis of mRNA at 0 degrees with dilute KOH before oligo(dT)-cellulose selection produced 5' mRNA fragments enriched with an alkali-resistant oligonucleotide with a -5 charge; the 3' mRNA fraction was correspondingly reduced in oligonucleotide content. Since methyl label disappeared at the same rate from both fractions, we conclude that mouse kidney contains short-lived mRNA and that the "caps" of these labile mRNAs turn over with the rest of the mRNA molecule.


Electron microscopy of DNA crosslinked with trimethylpsoralen: test of the secondary structure of eukaryotic inverted repeat sequences. It has been suggested that inverted repeat (palindrome) sequences, which are widespread in eukaryotic genomes, exist in two alternate configurations, a linear form and a cruciform. To investigate the relative frequency of these forms, the DNA of intact mouse tissue culture cells was covalently crosslinked with 4,5',8-trimethylpsoralen (me3-psoralen) in order to prevent rearrangement of the DNA secondary structure during DNA isolation. The distribution of me3-psoralen crosslinks was determined by electron microscopy after denaturation of the DNA in the presence of glyoxal. Because of the high frequency and the relatively uniform distribution of the me3-psoralen crosslinks, it could be concluded that almost all of the inverted repeat sequences had been crosslinked. In spite of this, no significant number of cruciforms was detected by electron microscopy. To determine whether the me3-psoralen might itself be disrupting cruciform structures, cruciforms were first produced in isolated Tetrahymena rDNA by heat treatment and then crosslinked in vitro. The crosslinking was found to stabilize rather than disrupt these cruciforms. We conclude that the inverted repeat sequences of the mouse tissue culture cells we tested are predominantly in linear forms rather than in cruciform structures inside the cell.


Linking numbers and nucleosomes.

Linking numbers and nucleosomes. In considering supercoils formed by closed double-stranded molecules of DNA certain mathematical concepts, such as the linking number and the twist, are needed. The meaning of these for a closed ribbon is explained and also that of the writhing number of a closed curve. Some simple examples are given, some of which may be relevant to the structure of chromatin.


Chemical characterization of the selenoprotein component of clostridial glycine reductase: identification of selenocysteine as the organoselenium moiety. A small, heat-stable selenoprotein, one of the components of the glycine reductase complex, was labeled with 75Se by growth of Clostridium sticklandii in the presence of Na2 75SeO3. The selenium-containing moiety, which is essential for the biological activity of the protein, was shown to be a selenocysteine residue. It was isolated as its Se-carboxymethyl, Se-carboxyethyl, and Se-aminoethyl derivatives from digests of the pure 75Se-labeled protein that had been reduced and treated with the various alkylating agents prior to hydrolysis. In each instance the 75Se-labeled moiety obtained from an alkylated protein sample and the corresponding alkyl derivative of authentic selenocysteine were indistinguishable. Several studies of the native selenoprotein detected a chromophore (UVmax 238nm) that appeared upon reduction of the protein with KBH4 and rapidly disappeared upon exposure to oxygen. This oxygen-labile chromophore is thought to be the ionized -SeH group of the selenocysteine residue.


Psoralen-crosslinked secondary structure map of single-stranded virus DNA. The photochemical crosslinking of DNA by 4,5',8-trimethylpsoralen (trioxsalen) has been used to freeze the secondary structures of single-stranded DNA molecules of bacteriophage fd at different ionic strengths. These secondary structures (hairpins or looped hairpins) have been visualized in the electron microscope. Most of the single-stranded circular fd DNA molecules show only one hairpin after irradiation at 15 degrees in 20 mM NaCl in the presence of trioxsalen. As the ionic strength is increased, more hairpins appear on the DNA molecules. To map these secondary structures, double-stranded supercoiled fd DNA (RFI) was cleaved with the restriction enzyme HindII, which makes only one cut on each RFI molecule. After denaturation and crosslinking of the linear single-stranded fd DNA (a mixture of viral and complementary strands), all the hairpins have been mapped on the DNA molecule with respect to this HindII site. The results show that these hairpins occur at specific sites. The most stable hairpin has been assigned to the position where the initiation site for the conversion of single-stranded fd DNA to the double-stranded covalently closed form has been mapped. The remaining hairpins map in or near regions corresponding to in vitro promoter sites on the fd DNA.


Mechanism of action of beta-bungarotoxin on synaptosomal preparations. The neurochemical activity of beta-bungarotoxin was investigated using a synaptosomal preparation of rat cerebral cortices. In preparations preincubated with [3H]choline in order to label acetylcholine the toxin caused a rapid release of the transmitter, which was calcium dependent but only a little affected by a depolarizing concentration of potassium. beta-Bungarotoxin was also shown to be a potent inhibitor of the high affinity transport system for choline, producing 50% inhibition at a concentration of 50 nM. These findings explain the observed electrophysiological effects of the toxin. Electron microscopy revealed no discernible effect of 0.1 muM beta-bungarotoxin on either synaptic vesicles or mitochondria. Neither the release of transmitter nor the inhibition of choline uptake by the toxin was affected by the presence of an inhibitor of phospholipase activity.


Isolation and characterization of the protein coded by gene A of bacteriophage phiX174 DNA. Replication of phiX174 circular replicative form (RFI) DNA by extracts of Escherichia coli infected with bacteriophage phiX174 (amber in gene A) requires the phiX174 gene A product. This requirement has been used as an assay for the isolation of this protein. The gene A product (purified 4000-fold) caused relaxation of superhelical phiX174 RFI and formation of discontinuities in the viral strand of phiX174 RFI uniquely situated in the A region of the genome, and yielded a complex after interacting with phiX174 RFI that is active in replication of phiX RFI.


(+/-)-7alpha,8beta-dihydroxy-9beta,10beta-epoxy-7,8,9,10-tetrahydrobenzo(a)-pyrene is an intermediate in the metabolism and binding to DNA of benzo(a)pyrene. The addition of borate buffer to the aqueous methanol used to elute hydrocarbon-deoxyribonucleoside derivatives from an LH 20 Sephadex column resulted in the separation of the products of reaction with DNA of the stereoisomers, (+/-)7alpha,8beta-dihydroxy-9alpha,10alpha-epoxy- and (+/-)-7alpha,8beta-dihydroxy-9beta,10beta-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrenes, i.e., the syn- and anti-benzo(a)pyrene-diolepoxide, respecitvely. By this technique it was shown that the microsome-mediated binding to DNA of benzo(a)pyrene-7,8-dihydrodiol involved exclusively the anti-benzo(a)pyrene-diolepoxide. The benzo(a)pyrene binding to DNA that resulted on exposure of BHK21/C13 cells to this carcinogen was also shown to result predominantly by reaction of the anti-benzo(a)pyrene-diolepoxide. However, in this case other derivatives, including the syn-benzo(a)pyrene diolepoxide, might also be involved.


Structural (shape-maintaining) role of the cell surface glycoprotein of Halobacterium salinarium. The obligate halophile, Halobacterium salinarium, maintains a rod-shaped morphology under normal growth conditions. Lactoperoxidase(EC 1.11.1.7;donor:hydrogen-peroxide oxidoreductase)-catalyzed iodination and treatment with proteolytic enzymes were used to demonstrate that the recently described envelope glycoprotein (Mescher, M.F. & Strominger, J.L. (1976) J. Biol. Chem. 251, 2005-2014) is the only major cell surface component of this organism. The morphological changes that accompany alteration of the structure of the glycoprotein by growth in the presence of bacitracin or its removal with proteolytic enzymes strongly suggest that it forms a rigid matrix at the cell surface and is responsible for maintenance of the characteristic rod shape.


1,N6-etheno-AMP and 1,N6-etheno-2'-deoxy-AMP as probes of the activator site of glycogen phosphorylase from rabbit skeletal muscle. Both 1,N6-etheno-AMP and 1,N6-etheno-2'-deoxy-AMP bind at the AMP site of phosphorylase b (1,4-alpha-D-glucan:orthophosphate alpha-glucosyltransferase, EC 2.4.1.1). Etheno-AMP induces the same activation as AMP, about 30-fold higher than the activation induced by etheno-dAMP. The fluorescence of etheno-AMP and etheno-dAMP is associated with the base moiety; therefore, when free in solution, the two derivatives have identical fluorescence properties. However, when bound to phosphorylase, the fluorescence of etheno-AMP is quenched more efficiently than the fluorescence of etheno-dAMP. This difference between the fluorescence properties of the bound nucleotides suggests that a modification in the ribose ring affects the position of the adenine in the AMP site of phosphorylase b. The observed quenching may be due to a stacking interaction between an aromatic residue and the base moiety of the bound nucleotide.


Membrane potential dependent binding of scorpion toxin to action potential Na+ ionophore. Depolarization of neuroblastoma cells causes a 70-fold increase in the apparent dissociation constant KD for scorpion toxin enhancement of activation of the action potential Na+ ionophore by veratridine and a large increase in the rate of reversal of scorpion toxin action. Depolarization also inhibits binding of 125I-labeled scorpion toxin to a small number of saturable binding sites on electrically excitable neuroblastoma cells and increases the rate of dissociation of scorpion toxin from these sites. The results suggest that scorpion toxin binds to a regulatory component of the action potential Na+ ionophore whose conformation changes on depolarization.


Direct spectroscopic observation of inner and outer hydrocarbon chains of lipid bilayer vesicles. Distearoylphosphatidylcholines labeled with gem-difluoro groups at selected positions of the fatty acid chains have been prepared. These lipids were incorporated into sonicated vesicles and were examined by fluorine nuclear magnetic resonance spectroscopy. All spectra are characterized by two well-separated fluorine resonances. Paramagnetic ions added to the exterior solution of vesicles of fluorinated lipid broaden the upfield resonances, whereas ions trapped in the vesicles interior broaden the downfield resonances. This demonstrates that the fluorine chemical shift of these compounds is sensitive to differences between the inner and outer monolayers of sonicated vesicles.


Regulation of protein synthesis in rabbit reticulocyte lysates: characteristics of inhibition of protein synthesis by a translational inhibitor from heme-deficient lysates and its relationship to the initiation factor which binds Met-tRNAf. In heme-deficient reticulocyte lysates a translational inhibitor which regulates protein synthesis is formed or activated. To define the mechanism of action of the translational inhibitor (RI), RI was partially purified. We have utilized the isolated RI to examine its relationship to the translational inhibitor formed in situ in heme-deficiency, some quantitative aspects of inhibition of protein synthesis, and the relationship of RI concentration to the initiation factor (IF-MP) which forms a ternary complex with Met-tRNAf and GTP (IF-MP-Met-tRNAf-GTP). The results demonstrate that the activity of isolated RI is related to the in situ heme-deficiency inhibitor by several criteria: (a) the biphasic kinetics of inhibition manifested by RI in lysates containing optimal levels of hemin are very similar to those observed in heme-deficiency, i.e., an initial period in which several rounds of protein synthesis proceed at the control rate followed by an abrupt decline in the rate of protein synthesis. (b) Both inhibitions are accompanied by the disaggreagation of polyribosomes with a concomitant increase in 80S ribosomes. (c) Both inhibitions are reversed by IF-MP. The isolated RI blocked protein synthesis in lysates at temperatures ranging from 15 degrees to 30 degrees. Although the rate of protein synthesis was a function of the temperature of incubation, the number of rounds of protein synthesis prior to shut-off was essentially the same at various temperatures. When RI was added to lysates, at increasing intervals after the start of incubation, the period of synthesis before shut-off (lag) progressively decreased. The inhibition of protein synthesis by RI was immediately reversed by the addition of IF-MP. The extent of reversal increased with increasing concentrations of IF-MP; at low levels of RI almost complete reversal of inhibition by IF-MP was obtained. However, at high levels of RI which did not appreciably increase the degree of inhibition of protein synthesis, equivalent amounts of IF-MP were less effective in reversing inhibition. These results suggest that the inhibition of protein synthesis by the isolated inhibitor involves the initiation factor IF-MP.


Control of renal vitamin D hydroxylases in birds by sex hormones. Kidney homogenates from adult male Japanese quail or chickens demonstrate hydroxylase activity predominantly for the 24 rather than the 1 position of 25-hydroxyvitamin D3 (25-hydroxycholecalciferol). A single injection of 5 mg of estradiol-17beta into a male bird completely suppresses the 24-hydroxylase and greatly increases the 1-hydroxylase activity. Immature males do not respond well to estrogen alone, but they do respond well to estradiol plus testosterone. Testosterone alone has little or no effect on the hydroxylases of either species. Castrated male chickens show an estradiol response only when testosterone is also given. Optimal 24 hr responses to 5 mg of estradiol per kg in the castrate male were obtained with about 12 mg of testosterone per kg. These optimal amounts of estradiol and testosterone increased the activity of 25-hydroxyvitamin D3-1-hydroxylase approximately 225-fold (this enzyme is also known as 25-hydroxycholecalciferol 1-monooxygenase; 25-hydroxycholecalciferol, NADPH: oxygen oxidoreductase (hydroxylating), EC 1.14.13.13). These results demonstrate a strong regulation by the sex hormones of the renal vitamin D hydroxylases in birds.


Thermodynamic fluctuations in protein molecules. Apparently conflicting views of the physical nature of globular proteins, and other macromolecules, may be reconciled by consideration of the inevitable thermodynamic fluctuations inherent in microscopic systems. Discrete protein molecules, considered singly, undergo sizeable fluctuations in thermodynamic properties which are manifest in their stochastic properties. This is not incompatible with time-averaged studies of ensembles of proteins from which a more compact, rigid, and static view of these molecules may be obtained.


Detection of mRNA sequences in nuclear 30S ribonucleoprotein subcomplexes. RNA from nuclear 30S ribonucleoprotein (RNP) complexes of mouse ascites cells has been shows to contain sequences homologous to poly(A) + mRNA by its ability to hybridize with complementary DNA prepared from poly(A) + mRNA template. Analysis of the hybridization kinetics of poly(A) + mRNA with its own complementary DNA revealed several abundancy classes. The total complexity of poly(A) + mRNA from ascites cells was estimated to be approximately 30,000 sequences of average molecular weight (6 X 10(5)). When the hybridization reaction of 30S RNP-RNA with mRNA-specific cDNA was compared to the homologous reaction the majority, and most probably all, of the poly(A) + mRNA sequences were found to be present in the RNA. The kinetics of hybridization suggest that 10-15% of the RNA in this RNP complex is homologous to poly(A) + mRNA. The 30S RNP subcomplexes therefore contain nuclear poly(A) + mRNA sequences as well as the bulk of heterogeneous RNA.


Defective thymine dimer excision by cell-free extracts of xeroderma pigmentosum cells. Crude extracts of normal human diploid fibroblasts and of human peripheral blood lymphocytes excise thymine dimers from purified ultraviolet-irradiated DNA, or from the DNA presumably present as chromatin in unfractionated cell-free preparations of cells that had been labeled with [3H]thymidine. Extracts of xeroderma pigmentosum cells from complementation groups A, C, and D also excise thymine dimers from purified DNA, but extracts of group A cells do not excise dimers from the DNA of radioactively labeled unfractionated cell-free preparations.


Bacteriophage T3 and T7 early RNAs are translated by eukaryotic 80S ribosomes: active phage T3 coded S-adenosylmethionine cleaving enzyme is synthesized. RNA transcribed in vitro from the early region of bacteriophage T3 or T7 was translated by cytoplasmic ribosomes which synthesized protein in cell-free systems prepared from mammalian cells and wheat germ. The proteins synthesized in vitro and their counterparts prepared from infected Escherichia coli comigrate by polyacrylamide gel electrophoresis with sodium dodecyl sulfate and are similarly affected by deletion or amber bacteriophage mutations. Bacteriophage T3 codes for an enzyme that cleaves S-adenosylmethionine and this activity was detected among the products of the mammalian cell-free system. Bacteriophage T3 or T7 RNA, after endoribonuclease III (EC 3.1.4.24) cleavage, gave higher levels of incorporation into phage T3 or T7 polypeptides than when an equivalent amount of the uncleaved RNA was added to the eukaryotic cell-free systems. Methylation of phage T3 or T7 RNAs is apparently not required for translation in either the wheat germ or mammalian cell-free system. The ability of T3 and T7 RNA to be translated in the presence of saturating amounts of natural eukaryotic mRNAs suggests that many prokaryotic genes introduced into mammalian cells might be expressed if they were transcribed in an appropriate form.


Inhibition of erythrocyte phosphate transport by high pressures. Pressures of 200-1000 atmospheres (20-100 MPa) are found to decrease significantly the amount of phosphate (H32PO4-2)transported into the rabbit erythrocyte under otherwise physiological conditions. Such compression does not cause irreversible morphological changes or result in membrane disruption. The findings are interpreted in terms of a lipid phase transition induced by the high pressure, which is propagated to the associated phosphate transport system by a physical mechanism.


Polycation-induced assembly of purified tubulin. Several different polycations have been found that can substitute for the microtubule-associated proteins, or tau factor, in facilitating assembly of tubulin that has been purified by ion exchange chromatography. In low concentrations of the polycation diethylaminoethyl-dextran, 7 mg of tubulin is pelleted per 1 mg of polycation added. Under conditions favorable to microtubule assembly the entire pellet is seen by electron microscopy to consist of "double wall microtubules", which are essentially identical to normal microtubules in subunit structure and arrangement. When assembly is inhibited approximately the same amount of tubulin is pelleted, but it is in the form of clusters of curved sheets or filaments apparently related to tubulin rings. When conditions are changed to favor assembly, the tubulin within these clusters appears to reassemble to form the double wall microtubules.


Quantitation of delta-crystallin messenger RNA during lens induction in chick embryos. Embryonic chick cells of the presumptive lens ectoderm are induced to differentiate into a lens by the optic vesicle, an outgrowth from the developing brain. This lens induction involves formation of the lens placode by cell elongation between about 44 and 50 hr of development, followed by invagination of the placode between about 50 and 55 hr of development. The amount of delta-crystallin messenger RNA (mRNA) in heads of embryos between 48 and 72 hr of development was determined by molecular hybridization with [3H]DNA complementary to purified delta-crystallin mRNA. An average of approximately 0.5 pg of delta-crystallin mRNA was found per embryonic head at 48 hr of development. This leads to approximately 265 molecules of delta-crystallin mRNA per lens cell, if one assumes that the mRNA is confined to the lens rudiment, as is indicated by immunofluorescence studies of delta-crystallin performed by other investigators. Pulse-labeling experiments with [35S]methionine indicated that the delta-crystallin mRNA is being translated already at this time. delta-Crystallin mRNA accumulated at an average rate of 1 molecule per cell per minute between 48 and 72 hr of development. Thus, by extrapolation, the initiation of delta-crystallin mRNA accumulation coincides with the initiation of lens placode formation at approximately 43-44 hr of development, which is some 8-9 hr after the initiation of lens induction by the optic vesicle. These data suggest that delta-crystallin synthesis is regulated by the accumulation of delta-crystallin mRNA during lens induction in chick embryos.


Interrelationship of hexosaminidases A and B: conformation of the common and the unique subunit theory. Human kidney hexosaminidase A (beta-N-acetylglucosaminidase; 2-acetamido-2-deoxy-beta-D-glucoside acetamidodeoxyglucohydrolase; EC 3.2.1.30) is a heteropolymer of two immunologically distinct subunits designated as alpha and beta. Hexosaminidase B, however, is a homopolymer comprised entirely of beta subunits. When human kidney hexosaminidase A was dissociated into its subunits by p-hydroxymercuribenzoate, three distinct proteins having isoelectric points of pH 7.2.5.4, and 4.3 were isolated. The fraction having an isoelectric point of pH 7.2, designated as beta fraction, was electrophoretically and immunologically identical to hexosaminidase B and was enzymatically active. The proteins having isoelectric points of pH 5.4 and 4.3, designated as hexosaminidase Ai and alpha fractions, respectively, were enzymatically inactive and crossreacted with antiserum against hexosaminidase A and not with antiserum against hexosaminidase B. Upon incubation of p-hydroxymercuribenzoate-treated hexosaminidase A with dithiothreitol,, hexosaminidase A activity, as well as antigenicity, was regenerated, indicating that alpha and beta subunits hybridize to form hexosaminidase A. Antibodies raised in rabbits against beta fractions reacted with both hexosaminidase A and B, whereas the antibodies against alpha and hexosaminidase Ai fractions reacted only against hexosaminidase A. This would indicate that both fractions are composed only of subunits unique to hexosaminidase A. The molecular weights of alpha,beta, and hexosaminidase Ai fractions were estimated to be 47,000, 120,000, and 180,000 respectively, by Sephadex gel filtration. Upon urea-sodium dodecyl sulfate polyacrylamide electrophoresis, each of the three fractions dissociated into a single polypeptide having a molecular weight of approximately 18,000. It is concluded that p-hydroxymercuribenzoate dissociates hexosaminidase A, (alphabeta)3, into its subunits, and the beta subunits can reassociate to form relatively stable hexosaminidase B, (betabeta)3, while the alpha subunits reassociate in both the dimeric state, alpha2, and a polymeric state, alpha8.


Decreased fidelity of DNA polymerase activity isolated from aging human fibroblasts. DNA polymerase (deoxynucleosidetriphosphate: DNA nucleotidyltransferase, EC 2.7.7.7 or DNA nucleotidyltransferase) activity, isolated from late and early passage cells of the diploid human fibroblast line, MRC-5, was compared. The level of activity dropped with increasing passage. In addition, when the fidelity of polymerization was monitored with four synthetic templates under a variety of conditions, it was observed that the enzyme from late passage cells was more error-prone. The possible relation of these observations to "senescence" of the fibroblasts is discussed.


Chromosome-mediated gene transfer between closely realted strains of cultured mouse cells. Gene transfer between two closely related mouse cell lines has been carried out, using as the vector a cell-free preparation of metaphase chromosomes and nuclei. Distinction between gene transferents and revertants of the recipient mutant phenotype was achieved by the use of a donor strain carrying a mutationally altered (8-azaguanine-resistant) hypoxanthine-guanine phosphoribosyltransferase (HPRTase; IMP:pyrophosphate phosphoribosyltransferase, EC 2.4.2.8). The transferred HPRTase gene is initially unstable; in nonselective medium, it is lost at a rate of about 0.1 per cell per generation. Stabilization occurs as a rare event, with a frequency on the order of 1 X 10(-5) per cell per generation. The unstable state can be maintained for at least 200 generations through serial passages of the transferent in selective medium. Under the conditions of cultivation used in these experiments, the unstable HPRTase-positive cells are eventually replaced by the stable HPRTase-positive cells in the population.


Radiation-induced mutations at mouse hemoglobin loci. In experiments designed to detect new mutations affecting hemoglobin, we irradiated the male or female parent in reciprocal crosses of two mouse strains that differ in alleles at the hemoglobin (Hba, Hbb) loci as well as at five other specific loci. Offspring were analyzed for hemoglobin properties (electrophoretic pattern, solubility, crystal pattern), serum albumin differences, erythrocyte lysis, reticulocyte count, and external appearance. Five hemoglobin variants were found among the mutants. In three, the genetic contribution from the irradiated father was not expressed with regard to the alpha-chain; one carried a tandem deuplication (the first known case in the mouse) involving Hbb; and one probably resulted from double nondisjunction of chromosome 7. The finding that major chromosome aberrations can mimic hemoglobin mutations indicates the need, in similar experiments, to follow F1 screening with thorough cytogenetic analysis. The variants in which there is nonexpression of the alpha chain may be the result of small deficiencies or of faults in transcription or translation. Mutation rates based on these three variants are not out of line with earlier specific-locus results, although confidence limits are still wide.


Radioimmunoassay for intact Gross mouse leukemia virus. A radioimmunoassay for intact Gross leukemia virus has been developed using 125I-labeled Gross virus grown in tissue culture and guinea pig antisera to Gross virus grown either in tissue culture or harvested from leukemic C3H(f) mice. Separation of bound from free labeled virus was effected using the double antibody method. The assay can detect fewer than 10(8) virus particles and has been used to measure the viral content of individual organs from inoculated leukemic C3H(f) mice and from Ak mice with spontaneous leukemia. Organs from noninoculated healthy C3H(f) mice crossreacted poorly in the system, virus generally being detectable only in the thymus and spleen and at low concentration. In some of the inoculated C3H(f) leukemic mice the viral content of as little as 0.5 mul of plasma is measurable. That this assay is for intact virus and not for soluble antigens of the viral envelope was proven by the observation that the immunoreactive material of plasma and extracts from thymus and liver of leukemic mice has a buoyant denisty in sucrose of 1.17-1.18 g/ml, corresponding to that of intact virus grown in tissue culture. With this sensitivity it may now be possible to quantitate viral concentrations in tissue and body fluids from the time of inoculation through the development of obvious pathology.


Increased ion permeability of planar lipid bilayer membranes after treatment with the C5b-9 cytolytic attack mechanism of complement. The ion permeability of planar lipid bilayers, as measured electrically, was found to increase modestly upon treatment with purified complement complex C5b,6 and complement components C7 and C8. The subsequent addition C9 greatly amplified this change. No permeability changes occurred when components were added individually to the membrane, or when they were used in paired combinations, or when C5b, C7, C8, and C9 were admixed prior to addition. Thus, there is a significant parallel between the permeability changes induced in the model membrane and damage produced in biological membranes by the C5b-9 complement attack sequence. The efficiency of membrane action by C5b-9 was critically dependent on the order in whcih components were added to the membrane. There were also differences in the electrical properties of membranes treated with C5b-8 and C5b-9, though in both cases the enhanced bilayer permeability is best attributed to the formation of trans-membrane channels. Collectively, the data are consistent with the hypothesis that the mechanism of membrane action by complement involves the production of a stable channel across the lipid bilayer, resulting in cell death by colloid-osmotic lysis.


Experimental myasthenia in Balb/c mice immunized with rat acetylcholine receptor from rat denervated muscle. A new model of an autoimmune disease of the neuromuscular junction was obtained by injection of acetylcholine receptor purified from rat denervated muscles into Balb/c mice. Anti-rat, then anti-mouse acetylcholine receptor antibodies, appear in mouse serum during the immunization procedure. Electrophysiological investigations performed on immunized mice reveal a neuromuscular block similar to that found in myasthenia gravis. Not a single mouse with objective signs of muscular weakness was lacking anti-mouse acetylcholine receptor antibodies but no correlation was found between their level and the severity of the disease.


Purine metabolism in adenosine deaminase deficiency. Purine and pyrimidine metabolites were measured in erythrocytes, plasma, and urine of a 5-month-old infant with adenosine deaminase (adenosine aminohydrolase, EC 3.5.4.4) deficiency. Adenosine and adenine were measured using newly devised ion exchange separation techniques and a sensitive fluorescence assay. Plasma adenosine levels were increased, whereas adenosine was normal in erythrocytes and not detectable in urine. Increased amounts of adenine were found in erythrocytes and urine as well as in the plasma. Erythrocyte adenosine 5'-monophosphate and adenosine diphosphate concentrations were normal, but adenosine triphosphate content was greatly elevated. Because of the possibility of pyrimidine starvation, pyrimidine nucleotides (pyrimidine coenzymes) in erythrocytes and orotic acid in urine were measured. Pyrimidine nucleotide concentrations were normal, while orotic acid was not detected. These studies suggest that the immune deficiency associated with adenosine deaminase deficiency may be related to increased amounts of adenine, adenosine, or adenine nucleotides.


Nonsuppressible insulin-like activity and thyroid hormones: major pituitary-dependent sulfation factors for chick embryo cartilage. Serum from hypothyroid hypophysectomized rats did not stimulate sulfation or incorporation of amino acids into chick embryo sterna. When such rats were treated for a short time with growth hormone (somatotropin), their serum stimulated incorporation both of sulfate and of amino acids. The different actions of the two types of sera were not due to changes in thyroid state. The results support the existence in serum of a sulfation factor for chick embryo cartilage that is dependent upon growth hormone. Highly purified preparations of nonsuppressible insulin-like activity from human serum stimulated incorporation of amino acids, and of uridine into RNA, in chick embryo sterna in vitro; chondrocytes prepared from this tissue had specific high-affinity binding sites for this insulin-like activity. However, sulfate incorporation was stimulated very little, unless serum from hypothyroid hypophysectomized rats was also present. When L-3,5,3'-triiodothyronine was added as well, the stimulation was enhanced further. From these and other experiments, we conclude that (i) nonsuppressible insulin-like activity or a closely related peptide is the growth-hormone-dependent growth and sulfation factor for chick embryo cartilage: (ii) a second, unidentified factor must be present for the insulin-like activity to stimulate sulfation; and (iii) stimulation of sulfation by thyroid hormones in vitro is additive to that of nonsuppressible insulin-like activity.


Circadian organization of the estrous cycle of the golden hamster. In constant dim illumination the hamster estrous cycle free-runs with a period that is a quadruple multiple of the concurrently recorded rhythm of wheel-running activity; both activity and estrous cycles are generated by biological clocks. Maintenance of stable phase angle differences between heat onset and running onset before and after treatment with deuterium oxide suggests that a common circadian system generates periodicities in estrus and activity. An organization of the estrous cycle is proposed in which the stimulus for the ovulatory surge of luteinizing hormone is generated by a circadian system that includes the suprachiasmatic nuclei of the hypothalamus. Various possible interactions of estradiol and photoperiod with the neurogenic stimulus for the luteinizing hormone surge are described and implications of different types of circadian organization of the estrous cycle for theories of sexual differentiation are considered.


Diphenylhydantoin (dilantin) gingival hyperplasia: drug-induced abnormality of connective tissue. Various degrees of gingival overgrowth may occur in individuals taking diphenylhydantoin, a drug used widely in the treatment of epilepsy. The tissue overgrowth is made up predominantly of collagen, and may therefore be a useful model for analysis of fibrosis and some other connective tissue abnormalities. Fibroblasts derived from the overgrown tissue exhibit a level of protein synthetic activity approximately twice that of comparable cells obtained from nonepileptic control individuals and from the gingiva of age-matched epileptics taking the drug but not exhibiting gingival enlargement. In addition, 20% of the protein synthesized by cells from the affected tissue is collagen, whereas collagen accounts for only about 11% of the total protein produced by control cells of both types. The drug appears to induce or select for fibroblasts characterized by enhanced levels of protein synthesis and collagen production. This alteration persists through several cell replications in vitro in the absence of drug.


Cyanoacrylate as an adhesive for other medicaments: a study with triamcinalone on the healing of experimental oral ulcers. This study was undertaken to determine whether cyanoacrylate can be used to adhere other medicaments to oral ulcers in the hope of promoting healing. Triamcinalone was chosen since it is used presently in pastes in the oral cavity. Sixty rats were dived into three equal groups. In each animal under anesthesia with ether, bilateral equivalent ulcers, 2 mm in depth and diameter, were made with the tip of a rongeur on the midlateral aspect of the tongue. The right side served as a control. The left side was experimental and received the following: group I--isobutyl-2-cyanoacrylate only; group II--powdered triamcinalone acetonide; group III--triamcinalone covered with cyanoacrylate. All materials were reapplied every 24 hours for 4 days. Two animals from each group (6) were sacrificed at 1, 4, and 8 hours and 1, 2, 3, 5, 14, and 21 days. The results indicate that a powdered medicament can be held in place on oral ulcers for at least 24 hours. The ulcers with cyanoacrylate revealed less edema and cellular response for up to 24 hours. Healing of the ulcers was neither promoted nor delayed in any group.


Effects of persistent selective suppression of ganglionic butyrylcholinesterase on steady state and regenerating levels of acetylcholinesterase: implications regarding function of butyrylcholinesterase and regulation of protein synthesis. Persistent selective suppression of the butyrylcholinesterase (cholinesterase; acylcholine acyl-hydrolase, EC 3.1.1.8) activity of the superior cervical, stellate, and ciliary ganglia of cats by the daily administration of tetramonoisopropyl pyrophosphortetramide, 3.0 mumol/kg, intravenously, for 6 days produced a significant elevation in the levels of ganglionic acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7). When the same procedure was preceded by the inactivation of over 95% of the ganglionic acetylcholinesterase by sarin, 2.0 mumol/kg, intravenously, the rate of regeneration of acetylcholinesterase was decreased. Results are interpreted as evidence that ganglionic butyrylcholinesterase may serve as a precursor to acetylcholinesterase, and that the level of butyrylcholinesterase may regulate the rate of acetylcholinesterase synthesis.


11beta-hydroxysteroid dehydrogenase in subcellular particulates of rat submandibular salivary gland. 11beta-hydroxysteroid dehydrogenase (11beta-HSD) was studied in intracellular components of the rat submandibular salivary gland. The difficulty in retaining 11beta-HSD activity during fractionation was overcome by using soybean trypsin inhibitor. Relatively pure subcellular particles were obtained by altering the initial centrifugal speeds used for the various fractions. 11beta-HSD was found to have its main activity in the crude nuclear fraction of the gland. Pure nuclei were isolated by centrifuging the crude nuclear fraction through 1.8-M sucrose at high speed, and these were found to retain the major enzyme activity. It was hypothesized that 11beta-HSD may influence genetic expression processes in salivary gland, but further work will have to be undertaken to investigate this possibility.


Lead health hazard in root calan filling material. It has been stated in the recent literature that the lead content of N2 endodontic filling material poses a hazard of lead otxicity to the patient. No clinical evidence in humans was offered in support of the statements. In the studies here reported, it was determined that endodontic fillings of RC2B, A U.S. variant of the N2 material, contain, per root-canal, a quantity of lead equivalent to permissible uptake of 10-15 days. It is believed lead is generally unavailable to the blood stream, due primarily to its being chemically bound, and secondarily to the known affinity of dentin for lead. It was found that the levels of lead in the blood of nine young male patients, sampled at intervals up to 90 days following placement of RC2B endodontic fillings, were mostly nondetectable, did not exceed 9 mug/100 ml in any instance, and were all far below the accepted hazard-indicating level of 40 mug/100 ml whole blood.


Saliva stimulation in dogs with permanent duct fistulae. Saliva fluids were collected from catheters inserted in the duct openings of permanent paratid and sublingual duct fistulae prepared in dogs. In anesthetized dogs stimulants applied to the tongue had no effect on saliva output. In awake dogs topically applied sucrose (1.25%-20%) had no significant stimulating effect on salivary secertion when compared to water control responses. Citric acid (1.25%-20%), applied topically, resulted in dose-related fluid increases, with parotid volumes consistently higher than sublingual volumes. Pilocarpine (0.125 mg/kg, IV), elicited similar saliva volumes in awake and anesthetized animals; sublingual secretions were higher than parotid volumes. For comparing drug secretion or saliva composition in awake and anesthetized animals, use of the same, preferable an IV, stimulant administered on a milligram perper-kilogram basis is suggested.


Ventilator-related extra-alveolar air in adults. Extra-alveolar air (EAA) developed in 38 patients during mechanical ventilation. High ventilatory pressures and destructive lung disease predispose to EAA. Pneumoretroperitoneum and pneumoperitoneum are more common forms of ventilator-induced EAA in adults than generally realized; an associated pneumomediastinum was always identified when one of the two disorders above resulted from ventilation. Retroperitoneal air was located laterally along the liver and in the flanks, and changed little with change in patient position. Early detection of EAA may allow life-saving changes in therapy to be implemented.


Biological active peptides in human urine: III. Inhibitors of the growth of human leukemia, osteosarcoma, and HeLa cells. Medium-sized peptides isolated from normal humans urine were tested for their effect on DNA, RNA, and protein synthesis, and mitosis, in tissue culture of human myeloblastic leukemia, osteosarcoma, and HeLa cells. Two types of antineoplastic peptides were found. One type consists of strongly acidic peptides (probably sulfated glycopeptides) which act specifically on different kinds of neoplasma. The other type comprises slightly acidic and neutral peptides, and has broad specificity. The active peptides produce up to 97% inhibition of DNA synthesis and mitosis in the neoplastic cells in tissue culture. The peptide fraction which has broad specificity was tested in different concentrations and gave good dose-response relationship.


Clinical tests of dentifrices.

Clinical tests of dentifrices.


Occlusal adjustment by grinding of teeth; indications and techniques. Occlusal adjustment by grinding of teeth is a therapy that all dentist can master, provided they base it on a knowledge of what constitutes an acceptable occlusion. There is hardly use for intricate or difficult rules and prescriptions for occlusal adjustment. After having diagnosed the occlusal condition in the patient, the dentist has to decide how to attain the goal : an acceptable occlusion without interferences, that is tooth substance that is in the way of harmonious function. Very often simple grinding of teeth can improve the occlusion of our patients. And in combination with other corrective measures, e.g. prosthetic rehabilitation and orthodontic treatment, occlusal adjustment by grinding deserves to be used much more frequently in clinical dentistry than it is today. It is a cheap and simple procedure that can improve our patient's occlusal hygiene. And occlusal hygiene is a concept that now should be incorporated in odontology as oral hygiene seems to have been universally accepted. And we dentists are even more responsible for increasing the quality of occlusion in our patients than we are for the standard of their oral hygiene.


Chromosome banding studies in Philadelphia chromosome positive myeloid leukaemia. A cytogenetic study of Ph1 positive myeloid leukaemia in both chronic and acute phases had been made by a chromosome banding technique. The translocation (t(9;22)(q34;q11), designated t(Ph1) was present in the myeloid cells of 43 of 44 patients; the exceptional case had normal number 9 chromosomes and a different translocation (t(19;22)(q13;q11)). A translocation additional to that involving the Ph1 was found as a stable abnormality present in all myeloid cells in 4 patients, chromosome 17 being involved in 2. The association of isochromosome number 17 with blast crisis was confirmed. New data were obtained concerning the significance of duplicated or dicentric Ph1 chromosomes and their relationship with the 9q+ anomaly. Monoclonal origin of Ph1 was confirmed in cases with polymorphic number 22 or 9 chromosomes.


Improved oral health of schoolchildren of 16 communities after 8 years of prevention. III. Gingival conditions and calculus. In 1963, a "Caries-Preventive Program" was started in the canton of Zurich. Within this program supervised toothbrushing exercises (with fluoride preparations) were carried out at school. They were performed 3 times per year by specially trained former dental chairside assistants who also discussed the usefulness of toothbrushing (10 min at each class visit). The teachers were expected to perform 3 additional supervised toothbrushing exercises during the year. The total number of brushing exercises per year was between 4 and 6. A total of 7548 examinations of children were made in 16 communities in 1963/64 1967/68 and 1971/72. The occurrence of gingivitis was studied by considering the symptoms of edematous swelling and discoloration. The frequency of both symptoms decreased over the study period 1963/64 to 1971/72. The frequency of supragingival calculus lingually on lower incisors was also reduced, but this result was not consistently found in the communities. In a subsample, subgingival calculus was studied on bite-wing radiographs. The percentage of children 13 to 15 years of age with such deposits decreased from 9.27 to 3.22.


A Dental Declaration of Independence.

A Dental Declaration of Independence.


Beware! Tricky landlords.

Beware! Tricky landlords.


Fluoride content of dental hard tissues with special respect to fluoridation of domestic salt. Teeth from children with various histories of fluoride supplementation were collected and analysed for fluoride. Fluoride concentrations in dentine from the canton of Vaud with fluoridated salt at 250 ppm since 1969 were at a level comparable to that reported from regions with 1.0 ppm F- in the drinking water and in children having received fluoride tablets during their tooth formative age.


Clinical examination of the vitreous.

Clinical examination of the vitreous.


Helix formation. Its involvement in the formation of gel structures.


Physical structures of the vitreous.

Physical structures of the vitreous.


Inflammation and its effect on the vitreous. The role of the vitreous in inflammatory diseases of the eye is now more clearly defined because of improved methods of examination and surgery. Inflammatory diseases of various aetiology produce opacification, liquefaction, and shrinkage. Additional changes include cellular proliferation and transformation leading to fibrosis in cases of prolonged inflammation. In some eyes the fibrosis is primarily cortical while in others it is extensive. Those inflammations with outpouring of a fluid exudate lead to detachment of the vitreous from the posterior eye and extensive shrinkage. In such eyes the vitreous becomes heavily organized and opaque in the central eye behind the lens, obscuring the view of the posterior fundus. In young eyes vitreo-retinal adhesions often form at the sites of inflammation, leading to traction on the retina and ciliary body; retinal tears may result from the traction. Exudate in many inflammatory vitreal inflammations tends to collect at the vitreous base where it organizes into scar tissue. The scar is formed by the retina and ciliary body, but there are also fibrosis-produced monocytes that become transformed into fibroblasts. Shrinkage of the new-formed scar can lead to disinsertion or peripheral tears of the retina. Specific inflammations such as chronic cyclitis and toxoplasmosis produce characteristic changes in the vitreous that can be recognized on clinical examination. Melanomas and reticulum cell sarcomas also produce a characteristic vitreous opacification.


Role of the pigment epithelium in vitreous pathology.


Pathology of vitreous membranes and the effect of haemorrhage and new vessels on the vitreous.


Role of the vitreous in the haemoglobinopathies. The vitreous is felt to play a significant role in the development of advanced proliferative sickle retinopathy. This is particularly true in Stages 3 to 5 of the Goldberg classification. A comparison with the classification of proliferative diabetic retinopathy by Davis is presented. The role of vitrectomy in this disorder has been considered.


Pathology of the vitreo-retinal border structures.


The vitreous in diabetic retinopathy.

The vitreous in diabetic retinopathy.


Fibroglial proliferation in pars planitis. In a 51-year-old patient with long-standing pars planitis, light and electron microscopical examination of the intravitreal 'snowbank' revealed a fibrovascular layer adjacent to the hyperplastic nonpigmented epithelium of the pars plana and an extensive fibroglial proliferation within the vitreous base. The fibrovascular layer consisted of well-differentiated capillaries, probably emanating from the peripheral retina, interspersed with aggregated vitreous fibrils. The fibroglial portion of the 'snowbank' was composed of fibrous astrocyte-like cells which had secreted basement membranes and larger diameter collagen fibrils. This fibroglial tissue was in direct continuity with an ultrastructurally similar preretinal membrane. No significant choroiditis or cyclitis could be demonstrated. It is hypothesized that, in pars planitis, a primary inflammatory process of the peripheral retina and vitreous base may stimulate the observed preretinal and intravitreal fibroglial proliferation.


The vitreous in retinal detachment.

The vitreous in retinal detachment.


Corneo-vitreal contact.

Corneo-vitreal contact.


The vitreous in glaucoma.

The vitreous in glaucoma.


Treatment of massive vitreous retraction. 1 Massive vitreous retraction must be diagnosed according to a well-defined set of criteria. 2 Massive vitreous retraction is treatable, despite Machemer's assertion this morning, in its contracting as well as immobile stages, but surgery must be carried out as soon as possible after the diagnosis is made. 3 Liquid silicone is the correct treatment and is not toxic to the human eye.


Vitreous replacement.

Vitreous replacement. The long list of substances used by ophthalmologists for vitreous replacement can be reduced to only three for four. Their use depends upon the surgical procedure. After trauma or cataract extraction and in vitreous surgery, saline is the best substitute; it is rapidly replaced by aqueous humour and no inflammatory reaction occurs. Retinal detachment surgery requires a highly viscous material, harmless to ocular tissues, and these criteria are met by Healon H. Whenever highly viscous hyaluronic acid is available, it should be used instead of saline or air (Regnault and Brégeat, 1973). Sulphahexafluoride gas has also been used to treat these difficult cases of retinal detachment but further experience is needed before a definite conclusion can be reached.


Open skies vitrectomy.

Open skies vitrectomy.


Indications for vitrectomy via the pars plana. Vitrectomy via the pars plana is a surgical technique with a wide range of applications, which should be understood by all ophthalmologists, for they allow the successful treatment of conditions for which there was previously no good therapy. On the other hand, the breadth of indications for this new surgical approach and the hopelessness of the prognosis with other treatments is a temptation for its misuse. Clear guidelines must be established as to when vitrectomy is indicated. Some such guidelines are proposed.


Percutaneous cervical radiofrequency cordotomy for intractable pain.


Bilateral renal cortical necrosis following monocytic leukemia.


A modification of the Amsterdam infant ventilator. An audible leak-alarm. An inexpensive audible leak-alarm based on photoelectric recording of the manometer setting for the Amsterdam Infant Ventilator is described. On account of its small dimensions it can also be built-in into other types of ventilators.


Editorial: neurology in Papua New Guinea.


Paralytic shellfish poisoning in Papua New Guinea. Paralytic shellfish poisoning is differentiated from other forms of poisioning from marine animals. An outbreak in a village near Port Moresby is described, and the clinical picture seen in that and subsequent cases (25 plus 3 fatalities) is discussed. The clinical manifestations of almost pure cerebellar incoordination, without other constant neurological signs, is emphasized and the name Ataxic Shellfish Poisoning is suggested. The aetiology whereby toxic marine plakton organisms are siphoned and filtered from the water and accumulate in shellfish is described.


Kuru.

Kuru. Theis report discusses problems involved in the diagnosis of kuru. The gentic and epidemiological pattern is also reviewed. This reveals a continuing overall reduction in kuru incidence with the disappearance of juvenile cases and increasing age of male kuru patients a reduction  in the age of female cases. The significance of these trends in relation to the transmission of kuru is discussed.


Auyana head nodders: essential heredo-familial tremor in the Eastern Highlands. The syndrome of essential tremor occurs commonly in parts of the Eastern Highlands District. This description of the clinical features is bases on experience of over 200 patients and the influence of some pharmacological agents on the severity of the tremor are recounted. The age and sex incidence in several related linguistic groups is shown to be much greater than in neighbouring areas; so that the disorder can be epidemiologically defined within geographic and ethnic boundaries.


Neurological admissions to Goroka Base Hospital - an eight month survey. Over eight consecutive months in 1972-1973 each patient admitted to Goroka Hospital because of neurological symptoms was investigated. The nature of the symptoms, the clinical features and the final diagnosis are reviewed; whilst the circumstances leading to hospital admission and eventual outcome of the illness are described.


Subacute combined degeneration of the spinal cord. This paper describes the clinical history of an adult male who was found to be suffering from subacute combined degeneration of the spinal cord. It is believed that this is the first report of this condition in Papua New Guinea.


Normal serum biochemistry in Papua New Guinean adults. Aean concentrations of some serum biochemical variables for healthy male and female adults are provided for six Papua New Guinean communities of varying diet and location. These average values, with normal regional, sex and age variations, are presented as a reference for those using serum biochemical indices in clinical diagnosis in Papua New Guinea.


Nonocular cancer in retinoblastoma survivors. From a review of the records of 2,302 patients with retinoblastoma collated from CPMC and AFIP, it was found that retinoblastoma patients who survived their original eye cancer have a high incidence of second nonocular malignancies. The second neoplasms occur almost exclusively (97.5%) in patients who have had bilateral retinoblastoma, although retinoblastoma is much more commonly unilateral. The second neoplasms have appeared between 1 and 42 years after the successful treatment of retinoblastoma and have been fatal in approximately 85% of cases. Seventy-one percent of patients develop tumors in the field of the radiation beam; many of these were following treatment with low doses of radiation and after short latent periods. Nineteen percent of patients develop tumors clearly out of the field of radiation (eg, osteogenic sarcoma of the femur). Retinoblastoma patients appear to be unusually radio-sensitive to low doses of radiation and develop tumors in the field of radiation following treatment of 3,500 rads. They have a high incidence of nonocular tumors clearly distant from the radiation beam develop nonocular malignancies even if no radiation has been given. The incidence of multiple malignancies in patients successfully treated for retinoblastoma appears to be higher than for any other primary malignancy whether they receive radiation or not.


Thermography of the breast. A clinical study with special reference to breast cancer detection.


Effect of chemical sympathectomy (6-hydroxydopamine) on gastrointestinal propulsion after laparotomy. An experimental study in the rat. The effect of chemical sympathectomy on gastric evacuation and small bowel propulsion 15 hours after a standardized laparotomy was evaluated. The animals were pre-treated with 50 mg/kg i. v. of 6-hydroxydopamine 15 or 48 hours or 150 mg/kg 48 hours before the evaluation of gastrontestinal propulsion. The treatment did not prevent the postoperative retardation. On the contrary 6-hydroxydopamine in itself seemed to retard gastrointestinal propulsion. In simultaneously adrenal demedullated rats no further retardation was produced by the laparotomy.


The adreno-medullary effect on gastrointestinal propulsion after laparotomy. An experimental study in the rat. Gastrointestinal propulsion after abdominal surgery is impaired during the postoperative phase. Adrenalectomy as well as only adrenal demedullation prevented the impairment of gastric emptying and small bowel propulsion after laparotomy. In non-laparotomized rats gastric evacuation was significantly increased after adrenalectomy and adrenal demedullation. The results indicate that adrenomedullary activity retards gastrointestinal propulsion not only postoperatively but even in intact rats.


Influence of ether anaesthesia and oro-gastric intubation on gastric evacuation and small bowel propulsion after laparotomy. A methodological study in the rat. A model for the simultaneous study of gastric evacuation and small bowel propulsion in the rat is presented. By means of a modification, with both indwelling duodenal and gastric tubes, studies on fully conscious animals were possible. Gastric evacuation and small bowel propulsion were analysed with respect to the effects of ether anesthesia and gastric intubation. The gastric intubation in ether anaesthesia greatly retarded gastric evacuation but left small bowel propulsion unaffected one day after laparotomy. The main factor retarding gastric evacuation appeared to be the oro-gastric intubation procedure. Ether  anaesthesia neither affected gastric evacuation nor small bowel propulsion after laparotomy when the test meal was deposited into the stomach and into the duodenum, respectively, via the permanent tubes.


Effect of adrenergic blockade on gastrointestinal propulsion after laparotomy. An experimental study in the rat. The effects of alpha-adrenergic and beta-adrenergic blockade on gastric evacuation and small bowel propulsion 15 hours after standardized laparotomy were evaluated. No retardation of gastric evacuation after the laparotomy appeared when alpha-receptor blocking treatment with phenoxybenzamine was instituted. Beta-receptor blocking treatment with propranolol did not prevent the retardation of gastric evacuation after the laparotomy. The time of analysis, 15 hours after the laparotomy, seemed to coincide with the period of resumption of normal small bowel propulsion.


Catecholamine infusion and gastrointestinal propulsion in the rat. The influence of continuous i. v. infusions of adrenaline, noradrenaline, noradrenaline and saline on gastric evacuation and small bowel propulsion was recorded. The infusions were given to fully conscious rats. Two differently labelled radioactive liquid test meals were administered directly into the stomach and the duodenum, respectively, via permanent tubes during the infusions. Both gastric evacuation and small bowel propulsion were significantly inhibited under the influence of the infused catecholamines.


Effects of sympatho-adrenal activity and pharmacological treatment on gastrointestinal propulsion in the early postoperative period. An experimental study in the laparotomized rat. Gastric evacuation and small bowel propulsion were greatly retarded two hours after laparotomy in the rat. Adrenal demedullation, chemical sympathectomy with 6-hydroxydopamine or treatment with a cholinesterase inhibitor (Neostigmin), an alpha-receptor blocker (Dibenyline) or metoclopramide (Primperan) did not improve the gastric evacuation. Chemical sympathectomy or treatment with metoclopramide, however, significantly improved small bowel propulsion. A significant reflux of duodenal contents to the stomach was found in several animals treated with the cholinesterase inhibitor or subjected to adrenal demedullation.


Comparative cytologic and histologic studies in oral leukoplakia. Comparative analysis of cytologic and histologic results and clinical types of 201 oral leukoplakias has shown: 1) an agreement between cytologic and histologic results in 76.6% of all cases; 2) an occurrence of carcinoma in 32.9% of the erosive leukoplakias in 3.2% of the verrucous leukoplakias, and none in the leukoplakia simplex group; 3) a higher efficacy of cytology in detecting malignancy in the erosive leukoplakia group.


Letter: Cytologic diagnosis of ganglioneuroblastoma.


Vaginal and cervical cytologic changes following laser treatment. Carbon dioxide laser treatment is a very effective mode of removal of small fragments of tissue from the cervix which causes minimal bleeding and trauma and is followed by rapid healing. Biopsy sections and particularly cytologic preparations obtained from the areas of laser action indicate that squamous and columnar epithelial cells and possibly fibrocytes in the underlying connective tissue are altered, appearing coagulated and elongated similar to cells which have been removed from an area of electrocautery.


Analysis of tooth marks in a homicide case. Observations by means of visual description, stereo-photography, scanning electron microscopy and stereometric graphic plotting. In 1957 a woman was murdered in Oslo. Her left breast exhibited tooth marks. A man was arrested and sentenced to life imprisonment partly because of the dental evidence. He never admitted guilt and filed a petition for retrial. The present author was appointed as new dental expert. The material consisted of the fixed breast, models of the bite mark and models of the teeth of the convict, and several photographs. By means of visual examination, a magnifying glass, a lens stereoscope and a stereomicroscope characteristic details were noted. Stereoscopic picture pairs were taken, the material was studied by means of scanning electron microscopy and a stereometricgraphic plotting method permitting the outline of the tooth mark or the biting edge of a tooth to be registered in great detail in all three dimensions in the form of a contour map. This method has not previously been applied in the analysis of tooth marks in human skin. These examinations revealed no discrepancies but showed many corresponding characteristic features between the tooth marks and the teeth of the convict, resulting in the conclusion that it is highly probable that the tooth marks in the breast were made by the teeth of the convict.


Degenerative disease in the temporomandibular, metatarsophalangeal and sternoclavicular joints. An autopsy study. The right temporomandibular, sternoclavicular and first metatarsophalangeal joints were removed post mortem from 39 subjects. The surfaces of the various parts of the joints were examined and evaluated according to a grading system. Repeated evaluation of the joints showed a good reproducibility of the grading system. Of the 33 temporomandibular joints, 12 showed deviations in shape. Degenerative disease was uncommon and seen in only 3 joints. The total "score for degeneration" showed only a weak correlation with age (r = 0.28, rs = 0.08). Degenerative disease was common in the 35 sternoclavicular joints. All joints except 7 showed degenerative changes. A moderate correlation was found between age and the score for degeneration (r = 0.58). Of the 39 metatarsophalangeal joints only 5 were allotted no points of degeneration. A moderate correlation was found between age and score for degeneration (r = 0.61). No significant differences of degeneration were found between sexes. The coefficient of correlation between the score for degenerative disease of the temporomandibular joint and the degeneration score for the sternoclavicular joint and the toe-joint were r = 0.22 (rs = 0.16) and r = 0.46 (rs = 0.44), respectively. The significant association of degenerative disease found between the toe-joint and the sternoclavicular joint (r = 0.54, rs = 0.54) was reduced (to r = 0.29) when age-dependence was excluded. The degenerative changes described in this material are probably mostly due to local factors.


The silent period in the masseter muscle of patients with TMJ dysfunction. The silent period (SP) following a jaw jerk elicited during sustained contraction in the masseter muscles has been studied in two groups of subjects, one with and one without, acute and distinct symptoms of TMJ dysfunction. The subjects with acute TMJ dysfunction symptoms showed significantly shorter latency and longer duration of the silent period and the period of their depressed activity (DA) was also significantly longer than in the group without TMJ dysfunction. The duration of the SP of both muscles was symmetrical in about 60% of subjects in each group. This study validates that the duration of the silent period may be a useful diagnostic tool of clinical interest.


The administration of respiratory therapy: aerosol therapy, techniques, and equipment.


Multispecies schistosomal infections of the female genital tract detected in cytology smears. Egg morphology of Schistosomes affecting man in Africa is described and illustrated with particular reference to the appearance of the ova of S. haematobium, S. mansoni and S. mattheei in Papanicolaou stained smears.


Comparison of two surgical methods in combined surgical-orthodontic correction of impacted maxillary canines. The post-treatment periodontal condition of impacted maxillary canines was examined in two groups of patients. In one group (n =34) the teeth were exposed in the mouth after removal of the bone and soft tissue covering of the crown. In the other group (n =22) the bone covering the crown was removed, whereafter the mucoperiosteal flap was sutured back. In both groups the orthodontic treatment procedures were basically the same. The mean treatment duration was 18 months after radical surgical exposure and 22 months after moderate surgical exposure. The teeth were examined 1-2 years after removal of the fixed appliances. Oral hygiene and gingival inflammation were approximately the same in both groups. The palatal pocket was deeper on teeth subjected to moderate surgical exposure, and the depth also varied more. The loss of fiber attachment was not significantly different except on the palatal surface, where it was greater after radical exposure and also varied more. The interdental bone height, which was measured on radiographs, varied more after radical than after moderate surgical exposure.


Aspiration biopsy cytology, mammography and clinical exploration: a modern set up in diagnosis of tumors of the breast. Six hundred and two mammary tumors were examined clinically, by mammography and cytology, with a histologic checkup following surgical biopsy. There were 247 cases of malignoma and 355 benign cases. The limited reliability of the individual methods is demonstrated, and it is shown that their combined use can improve the diagnosis. More malignomas are detected, and preoperative diagnosis is made more safely. If all three methods yield identical results, as was the case in 50.2% of the malignant and 32.7% of the benign lesions, the probability of diagnostic error is less than one per cent. With a malignoma thus established, surgical treatment may follow immediately, or irradiation can be started. In benign cases a surgical biopsy may be foregone and further developments may be awaited with due provision for regular control. If the three methods yield conflicting or doubtful results, elucidation by surgical biopsy and histology is indicated.


Tooth mortality and endodontic status of a selected population group. Observations before and after treatment. Tooth mortality and the frequency and distribution of endodontically treated teeth was studied in a Norwegian population group. The pre- and posttreatment situation was thus surveyed in 481 individuals with endodontic treatment. The middle aged and the female patients were overrepresented in the sample. At admittance the mean number of teeth per patient was 22.8, 2.6 of which had been endodontically treated. After comprehensive dental treatment, the corresponding figures were 21.5 and 3.7. During treatment extractions were performed in 48% of the patients, twice as often in the maxilla as in the mandible, 47% of the extracted teeth being molars. At admittance, root fillings comprised 83.5% of the total number of endodontically treated teeth, while pulpotomies were observed in about 15%. Retreatments were performed in 35% of the treated roots and in every other patients.


An in vitro method for toxicity evaluation of water-soluble substances. The purpose of the present investigation was to develop a simple method for the evaluation of reversible and irreversible toxic influences in a cell culture system. A cell monolayer established on the bottom of glass scintillation vials was exposed to a toxic substance (phenol). Changes in the DNA synthesis of the cells were utilized as a criterion of toxic influence, and were measured by recording the incorporation of tritium labelled thymidine using a liquid scintillation technique. The exposure of the cells to phenol caused a marked decrease in the rate of DNA synthesis when the phenol concentration was increased from 0.01 to 0.1%. The decrease in the DNA synthesis could be reversed by maintaining the cells in growth medium for 4 hours after the cell-phenol contact. The degree of reversibility was dependent on the cell-phenol contact time, the phenol concentration, and the cell line used. The simple test procedures and the quick and convenient obtainment of results simplify the assay of large test series and make the method particularly useful for screening tests.


The effect of calcium hydroxide and fluorides on human dentine. With the aid of scanning electron microscopy and microradiography, 45 teeth including 20 contralateral tooth pairs were studied to assess the effect on human dentine of (1) a 1 minute treatment with 3% NaF, (2) a dressing of Ca(OH)2 and (3) a dressing of Ca(OH)2 and CaPO3F after follow-up periods of 2-8 weeks. After NaF treatment the SEM revealed no sign of obliteration of the dentinal tubules, and on microradiograms no indication of increased density could be registered compared to an untreated control area. Under the calcium dressing the SEM revealed in 13 cases out of 20 (5 cases of 11 intrapair comparisons) a varying degree of constriction of the dentinal tubules. Constrictions varied from one tubule to another and ceased approximately 0.1 mm in the dentine. On the microradiograms no significant difference could be registered between untreated dentine and dentine treated with the calcium dressings. Dressings of Ca(OH)2 a combination of Ca(OH)2 and CaPO3F for 2 months, or a 1 minute treatment with a cavity cleaner containing 3% NaF can thus not be considered to result in a reliable obliteration of the dentinal tubules.


Needle aspiration of the breast--why bother? Needle aspiration biopsy for the examination of breast nodules is an accurate uncomplicated and rapid procedure. Of 1168 cases so examined, 127 were malignant with abnormal cells in 114. Case studies suggest that this procedure should be utilized in all palpable breast masses.


The cervical epithelial surface. III. Scanning electron microscopic study in atypias and invasive carcinoma in mice. The anatomy of the epithelial surface of the uterine cervix was investigated in 31 mice with scanning electron microscope (SEM). The cervox of 20 mice was painted twice a week during five months with 3,4-benzpyrene (BP) in acetone and in 11 mice with acetone alone. Only two of the 15 acetone or BP treated animals with histologic normal epithelium showed similar structures as those described earlier for the normal cervical epithelium of untreated mice. The remaining 13 animals had regular mosaics, intermediate or cobblestone structures covered with irregular microvilli with or without long, finger-like protrusions. Irregular mosaics, intermediate or cobblestone structures were seen in atypical epithelium. In atypias Grade III and in invasive carcinoma irregular cobblestone structures with cellular overlapping were present. Atypical and invasive carcinoma were usually furnished with irregular microvilli, irregular fragmented microrugae and finger-like protrusions. The proportion of mice having anisovillosis with finger-like protrusions increased with increasing degree of epithelial severity. Since pathologic SEM changes were observed in some treated mice having normal histology the possibility was entertained that alterations at the cellular membrane level may preceed the nucleocytoplasmic changes required for the recognition of atypical epithelium in conventional histologic preparations.


Cytologic presentation of transitional cell carcinoma metastatic to uterus.


The construction and use of diagnostic standards for primary radiographic caries. The aim was to establish diagnostic standards for primary approximal radiographic caries diagnosis. These were described with reference to ranking of subjects, mean "intermediate" score per subject, which was based on the majority diagnosis recorded by three examiners, and by category of a certainty scale for individual tooth surface scores. The results recorded by two fourth year dental students and two hygienists, when reading 40 pairs of posterior bitewing radiographs of children between 13 and 15 years of age, showed an acceptable level of agreement for ranking of subjects. Agreement was less satisfactory, when comparing the mean scores of these four examiners with the "intermediate" score per subject and with a standard for individual surfaces. The proposed standards do not represent true scores, but serve as guidelines, as they depend on the diagnostic level of the examiners on whose scores the standards are based, and on the diagnostic criteria employed.


Postnatal development of the human temporomandibular joint. I. A histological study. Temporomandibular joints from 61 humans, aged 2 days to 27 years, were examined histologically. Four layers of the condyle were studied in detail. The outermost layer was richly vascularised in new-borns but by 3 years of age it had become avascular and contained few cells. In neonates the cartilage layer constituted a large part of the condyle but soon decreased in thickness and by 5-6 years of age it constituted only a thin zone of the top of the condyle. In the proliferative zone, mitoses occurred up to 13-15 years of age. This zone then decreased in thickness; the number of cells decreased, while the amount of intercellular substance increased. At birth, the temporal component was flat and was lined by vascularised connective tissue which became richer in collagen with increasing age. The cartilage layer was lacking in the fossa but was present on the tuberculum. A proliferative zone in this cartilage could be seen up to the age of 17-18 years and cartilage having only few cells was found in adults. Remodelling processes were seen in all components of the joints. The significance of the remodelling seen in the fossa and on the mandibular neck is discussed with relation to condylar and periosteal growth of the mandible.


Cyanophilic bodies in cervico-vaginal smears. Thirty-six out of 171 (21%) cervico-vaginal smears that manifested pronounced squamous epithelial atrophy contained cyanophilic bodies about the size and shape of parabasal cells. These cyanophilic bodies have been misinterpreted as cancer cells. Patients whose smears contained cyanophilic bodies were likely to be elderly, at least ten years postmenopausal, and free of any gynecologic symptoms or abnormalities except those associated with previous surgery. Smears which contained cyanophilic bodies also contained numerous parabasal cells in various stages of degeneration, objects which closely resembled trichomonads, and a heavy background of granular material. A morphologic continuum existed between all of these elements. The conclusion, therefore, is that cyanophilic bodies, spurious trichomonads and the granular material are all derived from degenerating parabasal cells. It is suggested that cyanophilic bodies develop because of the diminished efflux of exfoliated epithelial cells and mucus associated with squamous epithelial atrophy. The ensuing stagnation of parabasal cells allows them to degenerate to an advanced degree. It appears that as some of the parabasal cells degenerative, their nuclear chromatin becomes widely dispersed throughout the cytoplasm, thereby forming cyanophilic bodies.


Childhood leukemia in Norway from 1963-1974 with special emphasis on own material. Childhood leukemia in Norway in the period 1963-1974 with special emphasis on own material. Acta Paediatr Scand, 65:529, 1976. -A nation wide up-to-date survey of childhood leukemia in Norway including 499 cases in the period 1963-1974 is presented. The median survival for all cases was about one year. Around 20% of the 499 cases were still alive in Novemeber 1974. Twenty-five of the children were off therapy without any signs of relapse. In our own material thirteen of 42 cases of acute lymphatic leukemia (ALL) were still in primary remission after 3-9 1/2 years. Twelve of them were still off therapy and none had relapsed. Best results were achieved in the 31 cases of ALL followed closely by us all the time. The number of cases in continuous complete remission and the median survival rate in this series compares favourably with the last two studies published by the St. Jude group.


An increased incidence of an androgen type cell in vaginal smears of pregnent women carrying femal foetus: possible significance.


Myocarditis associated with Echo type 7 infection in a leukemic child. A 3 1/2-year-old boy, during the course of acute lymphocytic leukemia presented clinical, roentgenological and ECG signs of myocarditis, which disappeared completely within 1 1/2 month. ECHO type 7 virus was isolated from the faeces during the acute stage of the disease and rise in ECHO 7 neutralizing antibodies was demonstrated in paired sera of the patient. This unusual pathogenicity of ECHO 7 virus could be explained with the impairment of the host resistance induced by leukemia and immunosuppressive therapy.


The apical level of root fillings.

The apical level of root fillings. The apical level of root fillings made by general practitioners, undergraduate students and an endodontist was compared. In total, 3003 root fillings were grouped morphometrically in three classes. Class A fillings were ending at a distance from the radiographic apex. Class B fillings were ending flush with the radiographic apex or with an overfilling of not more than 1 mm, while class C consisted of fillings with a moderate (1-2 mm) or marked (greater than 2 mm) excess. For 2187 class A fillings the distance from the apical end of the root filling to the radiographic apex was measured to the nearest 0.5 mm. The 531 class B and 285 class C root fillings were given the distance 0.0 mm. A detailed classification of root fillings with regard to their length was then developed by calculating the average distances and standard deviations. A longer apex-distance was observed for root fillings made by the general practitioners than for those made by the undergraduates and the endodontist. Class B and C fillings were infrequently observed among fillings made by general practitioners. Roots from three-rooted teeth had been filled closer to the radiographic apex by the endodontist than by undergraduates. A higher relative number of class C fillings was observed for undergraduates than for the endodontist, while the opposite observation was made for class B cases.


Identification of abnormal cells in short term monolayer cultures of human tumor specimens. This work was undertaken to verify that when short term monolayer cultures are prepared from human malignant biopsy specimens, the cells which grow are tumor cells and not normal cells from the stroma. A wide range of human tissues, both normal and malignant, was used to obtain monolayer cultures and chromosome spreads were prepared by a modification of standard procedures. The cells were Feulgen stained and DNA values were obtained for cells arrested in mitosis. Metaphase DNA values for normal cells and for cells from a benign tumor were constant, close to the expected value relative to bull sperm, and showed little spread about the mean. Metaphases from malignant cells had abnormal mean DNA values, and generally showed much greater spread about the mean. Results confirm that for cells grown in vitro from tumor biopsies, those which are in the cell cycle and reach mitosis are abnormal and presumably malignant. This is evidence in favor of this type of short term culture as a method for studying the properties of human tumor cells.


The somatic development of children in a swedish urban community.


Letter: Toxoplasma cysts in vaginal and cervical smears.


VI. Somatic pubertal development.

VI. Somatic pubertal development. The pubertal development of 212 randomly selected Swedish urban children has been investigated as part of a prospective longitudinal study of growth and development. The timing and pattern of pubertal changes were in agreement with the findings in other contemporary studies. The good agreement with data on pubertal development reported in other investigations of Swedish children indicates that the present sample was representative of contemporary Swedish children. Two procedures of assessment of secondary sex characters - clinical examination and whole-body photography - have been compared and contrasted. A clinical examination is less laborious and resource-consuming and also has psychological advantages but should be supplemented in boys by the estimation of testicular volume (orchidometry). In girls the two methods have similar precision and reliability. The first pubertal changes may be observed before 9 years in girls (breast development) and before 10 years in boys (genital development). On average the first change takes place about one year earlier in girls than in boys. Peak height velocity (PHV) is an early event during puberty in girls and a relatively late event during puberty in girls and a relatively late one in boys, the sex difference in mean age being about two years. In girls, menarche is a late event, always occurring after PHV. At the age of 13-14 years some boys and girls have not yet begun theri pubertal development, while others have reached the adult stage.


Actinomycetes in cervico-vaginal smears: an association with IUD usage. A hitherto undescribed occurrence of actinomycetes in cervico-vaginal smears of IUD users is reported. The morphology of actinomycetes in Papanicolaou stained smears is described. The differential diagnosis and the significance of these observations is discussed.


Meningeal mycosis fungoides: cytologic and ultrastructural aspects. Mycosis cells were identified in the pre-morbid cerebrospinal fluid of a patient with neurological symptoms and mycosis fungoides (MF). Light and electron microscopic examination at autopsy confirmed leptomeningeal involvement by mycosis fungoides. The cellular morphology of the non-cutaneous infiltrates supports the concept that mycosis fungoides retains a unique histopathology in its dissemination to the viscera. The importance of cerebrospinal fluid cytology in patients with mycosis fungoides is emphasized.


Cytophotometric studies in suspicious cervical smears. Papanicolaou stained smears of various cervical lesions diagnosed as "suspicious" by routine cytology were reviewed with regard to different cell types leading to this diagnosis. The smears were then submitted to Feulgen hydrolysis and redyed by Acriflavin-SO2 for fluorescence-cytophotometry. In nine of 14 cases measured, the DNA content of all types of "suspicious" cells was increased with DNA modes at euploid levels of 2 n, 4 n and 8 n indicating that the "suspicious" cells in those cases are polyploid. However, in five cases aneuploid DNA-distribution patterns were found similar to those observed in carcinoma in situ or severe dysplasia. Since polyploidization may be considered as a cellular response to higher functional requirement (i.e. inflammation or regeneration) a "suspicious" cervical smear with a polyploid DNA-distribution pattern may reverse to normal cervical epithelium after normal conditions are restored. However, a "suspicious" smear with an aneuploid DNA-distribution pattern should be considered more seriously as being related to a precancerous lesion requiring immediate surgical treatment.


VII. graphic analysis of biological maturation by means of maturograms. The attainment of various maturity criteria has been analyzed by probit analysis using a logarithmic time concept (logarithmic conceptional age). The resulting probit lines have been plotted in charts-maturograms -using the x-axis as an age-scale and the y-axis as a marker of standard deviations scores. The slope of the probit lines is in such a direction that early occurrences are assigned positive SD-scores and late ones negative scores. The maturity criteria can be divided into two catergories- sequential (e.g. number of erupted teeth) or non-sequential (e.g. the menarche). When examined a child is observed to be within a certain stage of maturity. The observation can be evaluated with a cross-sectional or a longitudinal approach. The latter requires repeated examinations. The evaluation will result in a relative scoring (SD-scores) of the observations, i.e. a relative maturity level is calculated. The practical procedure has been exemplified for pubertal and dental development. Two sets of charts-pubertograms-have been constructed for the assessment of pubertal development in each sex. For dental development there are also two sets of sex-specific charts -dentograms- one for the deciduousdentition and one for the permanent dentition. Individual patterns of maturation can be analyzed by plotting the estimated SD-scores of the various maturograms. Individual variations in the trends of the estimated SD-scores may be an indication of different velocities of maturation.


I. physical growth from birth to 16 years and longitudinal outcome of the study during the same age period. Physical growth of 212 randomly selected Swedish urban children has been investigated from birth to sixteen years as part of a prospective longitudinal study of growth and development. Twenty body measurements have been taken at specified ages. In all, about 66,000 values of measurement have been recorded. At sixteen years 179 (84.4%) ofthe original children were still regularly being followed. Thirty-three (15.6%) of the 212 children left the study at various ages. A comparison between the children who left the study and those remaining did not show any significant differences in physical growth. All recorded data have been scrutinized in order to detect errors of measurement or administrative errors. Such values have been corrected or excluded. The editorial procedures also included the adjustment of each measurement to exact target age, interpolation of missing examinations and exclusion of children with an aberrant growth pattern. When comparing the present study with older Swedish investigations a secular trend was established, while there was good agreement with other contemporary Swedish investigations. Growth charts of distance values of various body measurements are presented. In the charts standard deviation lines (+/- 1, 2, 3 SD) and mean values are plotted. A logarithmic time scale (logarithmic conceptional age) has been used for both practical and theoretical reasons. When evaluating individual values in comparison with reference values standard deviations should be used rather than centiles. With this approach even grossly deviating values can be evaluated. Longitudinal follow-up of individual children and comparison of children of different ages will also be facilitated by this approach.


II. evaluation of biological maturation by means of maturity criteria. Maturation may be conceived of as a series of gradual transformations through time going on in the human body from conception to death as part of the life cycle of the organism. Maturity should be used as the general concept of any specified stage - or level -during the process of maturation. The maturity level can be assessed by examining the attainment of various maturity criteria relating to dental development, skeletal development and pubertal development. In a group of children the attainment can be analyzed by probit analysis using a logarithmic time concept (logarithmic conceptional age). This is exemplified by the attainment of breast stages according to Tanner (10) in the girls of the present study. When examined a child will be rated as being within a certain stage of maturity. The least advanced and the most advanced maturity level consistent with the rating can be established using the probit lines. The relative maturity level is then expressed in SD-scores of the Gaussian fitted distributions of age at attainment of various maturity criteria in a reference group of children. This is a laborious approach when there are many series of maturity criteria, e.g. in the assessment of skeletal maturity. In such cases each stage is instead given a certain maturity score. The individual maturity level is calculated by averaging the maturity scores of the stages, which are then evaluated in SD-scores by comparing with the Gaussian fitted distribution of averaged maturity scores at that age. In both approaches discussed in this paper the evaluation of individual maturity is made with a relative scale of measurement. Accordingly, the rate of maturation can only be assessed indirectly.


III. dental development from birth to 16 years. Tooth eruption in 212 randomly selected Swedish urban children has been investigated from birth to 16 years as part of a prospective longitudinal study of growth and development. The ages and the order of eruption of the deciduous and permanent teeth were in agreement with those reported in other contemporary studies. The good agreement with another longitudinal study of the tooth eruption of Swedish children born during the same period is an indication that the present sample was representative of contemporary Swedish children. In the deciduous dentition a probable male advancement was found, while girls were consistently the advanced sex as regards the eruption of permanent teeth. Sex differences have also been found in the relation between dental development and other criteria of somatic growth and development. The correlations were low or moderate with, in general, higher values for girls than boys. A positive association with somatic growth was observed both for the deciduous and the permanent dentition but with intriguing sex differences for various body measurements.


Hypokalemia in children with leukemia in relapse. Eight children with acute leukemia in relapse were hypokalemic during their hospital course. All had accompanying hypophosphatemia, and three had mild metabolic alkalosis. Potassium chloride supplementation in each case resulted in resolution of the electrolyte and acid-base disturbances. These findings were not present in patients with conditions newly diagnosed or those in remission. The pathogenesis of the electrolyte and acidbase disturbances was not evident and was not related to antibiotic or cytotoxic drug therapy, but may have been related to the patients' poor nutritional status. Seven of the eight patients died within six months of the hypokalemic episode. Hypokalemia may be a common accompaniment of terminal leukemia.